1. Field of the Invention
The invention relates to a sheet conveying apparatus for conveying a sheet, and an image reading apparatus for reading an original conveyed by this sheet conveying apparatus. The invention also relates to an image reading and forming apparatus provided with the image reading apparatus and an image forming apparatus for forming an image on a sheet on the basis of the image reading information of the image reading apparatus.
2. Description of Related Art
There have heretofore been sheet conveying apparatuses for conveying a sheet (see Japanese Patent Application Laid-open No. H10-126569 and Japanese Patent Application Laid-open No. H10-17176).
FIG. 5A of the accompanying drawings is a schematic front cross-sectional view of a sheet conveying apparatus described in Japanese Patent Application Laid-open No. H10-126569. This sheet conveying apparatus 101 is provided with a U-shaped conveying path 102 and is incorporated in an image reading apparatus for reading an original and therefore, a reading portion 103 for reading an original is provided in the conveying path 102. In the sheet conveying apparatus 101, the lower outer guide 102a of the conveying path 102 is formed in a scanner unit 104 fixedly disposed on the lowermost surface thereof. An original conveying unit 105 in the upper portion of the apparatus is pivotally movably provided on the scanner unit 104 by a bearing portion 106. When a user upwardly pivotally moves the original conveying unit 105 in an upper portion including an upper outer guide 102b (FIG. 5B of the accompanying drawings) when the original clogs, the lower outer guide 102a is opened so that the clogged original (jammed original) can be removed.
FIGS. 6A, 6B and 6C of the accompanying drawings are schematic front cross-sectional views of a sheet conveying apparatus described in Japanese Patent Application Laid-open No. H10-17176. This sheet conveying apparatus 201 is also provided with a U-shaped conveying path 202. This sheet conveying apparatus 201 is also incorporated in an image reading apparatus for reading an original. In the sheet conveying apparatus 201, the lower outer guide 202a of the conveying path 202 is formed on a scanner unit 204 fixed disposed on the lowermost surface of the apparatus. An original conveying unit 205 in an upper portion is pivotally movably provided on the scanner unit 204 by a bearing portion 206. The original conveying unit 205 is formed by a roller housing 207 and a cover 208.
The sheet conveying apparatus 201 shown in FIG. 6A is designed such that when a user upwardly pivotally moves the original conveying unit 205 (FIG. 6B) when an original clogs, the lower outer guide 202a is liberated and the original (jamming original) clogging on the lower outer guide 202a can be removed. Also, design is made such that when the cover 208 is opened, the original (jamming original) clogging on an upper outer guide 202b (see FIG. 6A) can be removed (FIG. 6C).
However, in the conventional sheet conveying apparatuses 101 and 201, it is often the case that the original conveying units 105 and 205 raised by the user are usually provided with parts such as a drive system such as a motor, a conveying roller, a gear and a clutch which are high in operation accuracy and heavy in weight. Moreover, the upper outer guides 102b and 202b are also raised together with the original conveying units and therefore, the original conveying units 105 and 205 have been heavier.
Thus, the user had to raise the heavy original conveying unit 105, 205 by one hand and remove the jamming original by the other hand.
Accordingly, the conventional sheet conveying apparatuses have suffered from the problem that it is difficult to do the work of removing the jamming original. Also, much time has been required for the work of removing the jamming original.